Device for creating tension in a travelling strip



E. A. PAULS June 30, 1970 DEVICE FOR CREATING TENSION IN A TRAVELLING STRIP Filed 001:. 9, 1967 a Sheets-Sheet 1 n ll n lluuil I "MIN '"I I IIIIHIIHIII III nventor flw/NA 2404s 9 XMMMWW L 6/ w fittormgs June 30, 1970 E. A. PAULS 3,517,894 I DEVICE FOR CREATING TENSIQN IN A TRAVELLING STRIP Filed Oct. 9. 19s? a Sheets-Sheet 2 [aw/m A. 241/15 by Mqmfidh, 5M}

fi omega United States Patent 3,517,894 DEVICE FOR CREATING TENSION IN A TRAVELLING STRIP Edwin A. Pauls, 541 S. Ashland, La Grange, Ill. 60525 Filed Oct. 9, 1967, Ser. No. 673,859 Int. Cl. B65h 77/00 US. Cl. 242--75.2 14 Claims ABSTRACT OF THE DISCLOSURE A device for creating tension in a travelling strip, including a platen defining a surface positioned in contact with the strip and an electromagnet mounted on the platen for causing a force to be applied to the strip urging the strip against the surface of the platen so as to create a frictional drag on the strip.

The present invention relates to apparatus for creating tension in a travelling strip and, more particularly, to such apparatus in which the tension is created by means of a frictional drag applied to the strip.

In the handling of strip material of considerable length, particularly metallic material such as a steel strip several thousand feet in length, it is frequently desirable to impart tension to the strip or control the amount of tension in the strip. For example, in the coiling of strip steel, the amount of tension in the strip determines the tightness of the wrap, a tight wrap being desirable in that it renders the resulting coil easier to handle. In the slitting of a strip of relatively large Width into a number of bands, each of considerably lesser width, it is customary to coil all of the bands simultaneously in spaced apart relation to each other on a single mandrel or reel. If uniform tension is not maintained on all of the bands, some bands may initially wrap loosely so that the coils which they form increase in diameter more rapidly than coils from bands which initially wrap tightly. The larger diameter coils eventually require more band length for each rotation of the reel than the tighter wrapped coils. The demands of these larger coils soon create a tension on those bands which form the coils which is much greater than the tension on the bands forming the smaller coils. As a result, some of the slit coils may be loosely wound, others tightly wound, and all may have soft and hard segments within them.

Also, bands slit from strip stock not held under suflicient tension do not track well as they are coiled, resulting in oscillated coils, i.e., coils wider than the strips from which they are formed. Hence, it is necessary to separate the bands on the rewind reel by means which sometimes damage the edges of the bands as they are coiled. Frequently, the means employed makes removal of the coiled bands from the reel more difiicult.

In addition, it is sometimes desirable to recoil slit bands in an oscillated fashion by oscillating the rewind reel along its axis of rotation as it revolves. When a band is wound in this manner, a spool of reduced diameter rather than a coil results. However, this form of winding is presently considered practical for only a single band at a time because of the difficulty of maintaining uniform tension on several bands. Thus, the strip is conventionally slit into bands, the bands coiled, and the individual coils then recoiled in spool form.

Finally, metal in strip form is frequently passed through roller levellers to flatten it. In passing through the roller leveller, the strip is frequently maintained in tension by a series of bridle rolls which it passes around. These rolls are expensive both to manufacture and to machine.

3,5 17,894 Patented June 30, 1970 ice It is the principal object of the present invention to provide an improved apparatus for creating tension in a travelling strip.

A related object of the invention is to provide an improved apparatus for coiling strips or bands.

Other objects and advantages of the invention will become apparent with reference to the following description and the accompanying drawings.

In the drawings:

FIG. 1 is a fragmentary partially broken-away side elevational view showing various of the features of the invention;

FIG. 2 is a fragmentary plan view of the apparatus shown in FIG. 1 with clamp 44 omitted;

FIG. 3 is an enlarged fragmentary partially brokenaway perspective view of a portion of the apparatus shown in FIGS. 1 and 2;

FIG. 4 is an enlarged perspective View of a portion of the apparatus shown in FIG. 1; and

FIGS. 5 and 6 are diagrams of certain of the wiring circuits of the device shown in FIGS. 1 and 2.

Very generally, a device 10 is shown in the illustrated embodiment of the present invention which is adapted to impart tension to a travelling strip or band 12 formed of a ferromagnetic material. In the illustrated embodiment, the device imparts tension to four such bands simultaneously. The device includes a platen 14 having an upper surface 16 over which the bands pass and against which the bands are urged under pressure as a result of a magnetic attraction created by electromagnets 18. Pressure engagement of the bands with the upper surface 16 of the platen creates a frictional drag on the bands and thereby imparts tension to them.

It is contemplated that the device 10 will be incorporated into an apparatus for working or otherwise treating the strip material such as a slitting apparatus adapted to separate a wide strip into relatively narrow bands which are then wound into separate but closely spaced coils on a common reel 22. However, it should be understood that the device of the invention might also be used to impart tension to the strip prior to entering the slitting apparatus or might be incorporated into other apparatus, including levellers, recoilers, and plating, cleaning and annealing apparatus, etc. without departing from the scope of the invention.

In the illustrated embodiment, the reel 22 is of the type which can be collapsed after the coil 24 has been fully wound to permit removal of the coil from the reel. The reel includes an extension 26 (FIG. 2) which is connected to a suitable power source (not shown) capable of imparting rotation to it.

The device 10 is positioned immediately adjacent the entry side of the reel, i.e., the side of the reel from which the bands 12 to be coiled are introduced, and is located intermediate the reel and a looping pit which is not shown but which is located to the left of the device 10 as the device is illustrated in the drawings. Thus, the bands leave the looping pit and pass upwardly and laterally in the direction of the reel 22.

Referring now more specifically to the structure of the device 10, the platen 14 (FIG. 3) includes a top plate 28 so shaped as to define a gradually curving supporting surface which guides the bands 12 from a generally vertical disposition in the looping pit to a generally horizontal disposition in which they are generally tangent to the coil 24 forming a nip at the uppermost portion thereof. The top plate 28 is preferably formed of a non-magnetic but rigid material such as aluminum, copper, or plastic, and is secured to a pair of horizontally spaced vertically disposed side plates 30, the upper edges of which have a curve corresponding to that of the top plate. Suitable transverse struts or the like (not shown) may also be provided to rigidify the platen.

Positioned beneath the top plate 28 and suitably supported adjacent thereto are a plurality of the electromagnets 18, each of which is shown as having a U-shaped core defining a pair of horizontally spaced pole pieces wrapped with electrical windings 34. In the illustrated embodiment, the magnets are arranged in four rows, with three magnets in each row, i.e., one row for each of the bands being coiled. By virtue of this arrangement, a different degree of tension may be imparted to each band relative to the other hands. If desired, however, a single row of magnets may be provided, with each magnet being essentially the width of the top plate 28 and extending between the side plates 30.

As seen in FIG. 5, the windings of the magnets of each row are connected in series with each other and with a variable resistor 36, with the windings of the magnets of each row being connected in parallel with the windings of the magnets of the other rows and in series with a common variable resistor 37, a switch 38, and a source of direct current, as represented by a battery 40. Thus, one of the variable resistors 36 can be adjusted to control the tension imparted to a single band by one row of magnets, while the variable resistor 37 can be adjusted to simultaneously control the tension imparted to all of the bands.

It is believed desirable that a magnetic force of attraction not be applied to the bands at the entry and discharge edges of the platen (the left and right edges, respectively, as viewed in FIGS. 1 and 2). To accomplish this, a thick transversely extending ferro-magnetic bar (not shown) may be located at each of these points so as to deflect the field beneath the top plate 28, or the magnets can be spaced sufficiently from these edges so that the effects of the field will be minimal at the edges. The top plate 28 of the platen is provided with a covering 42 to insure that the surfaces of the bands 12 will not become scratched as they pass over the platen. Various forms of coverings may be used, and a durable flannellike textile fabric of the type commonly referred to as buff cloth is suggested. Conceivably, however, materials other than a textile fabric such as, for example, a layer of a tetrafiuoroethylene polymer, sold under the trademark Teflon, might also be suitable. It is desirable to attach the covering to the platen in such a manner that it can be easily replaced when it becomes worn. For example, it may be attached to the platen by means of a clamp 44, as shown in FIG. 1.

Thus, when the switch 38 is closed and the windings 34 are energized, the magnetic field created attracts the bands 12 so as to draw them into pressure contact with the covering 42, thereby imparting tension to the bands by virtue of the frictional drag created on the hands. This drag will, of course, increase as the strength of the magnetic field is increased so that the tension in the bands may be varied by means of the individual variable resistors 36 or the common variable resistor 37.

Mounted on the platen 14 adjacent its entry end by means of a bracket 45 is a guide roller 46 which includes roller segments separated by guide discs 48. As shown, there is a separator disc 48 adjacent each edge of each band 12 or a total of five discs for the four bands. The discs insure that the bands will be separated upon engaging the platen. It is anticipated that the magnetic forces acting on the portions of the bands in engagement with the platen will maintain the relative positions of the bands and cause them to track accurately until they are wound into coil form. That is, separation or spacing of the bands can be accomplished by magnetic fields set up by the magnets. Specifically, the lines of magnetic force in each band travel in the same direction. Accordingly, magnetic repulsion fields of like polarity exist between adjacent bands, which cause the bands to repel one another to effect separation and spacing. Adjacent the opposite or dis- 4 charge edge of the platen, mounted by means of a bracket 49, is an idler roller 50 which insures that the bands will pass freely olf the top plate 28 and covering 42 into the coil 24.

The platen 14 is supported by means of a frame 52 which includes a pair of vertically disposed side walls 54 suitably interconnected and spaced horizontally a distance greater than the width of the widest stock to be accommodated. As the coil increases in diameter, it forms at least partially in the space intermediate the walls 54, as shown in phantom in FIG. 1. That is, in expanding to the left as seen in the drawings, the coil expands past the adjacent edges of the walls 54 into the space between the walls so that it would not be possible to remove the coil by moving it axially of the reel, in the conventional manner, without moving one of the reel or frame away from the other. Accordingly, the frame 52 is mounted for sliding movement along horizontal rails 56 which extend in a direction away from the reel 22. The frame is therefore movable toward and away from the reel 22 along the rails 56, occupying the position shown in FIG. 1 when the bands are being coiled and being movable to the left to clear the fully formed coil only for removal of the coil. Movement of the frame may be accomplished in numerous ways, such as by means of the hydraulic cylinder 58 shown in FIG. 1.

It is desirable that the bands 12 be generally tangent to their respective coils at the nip or line of Contact between the band and the outer wrap of the coil. In such an instance, the band will be generally horizontal as it enters the coil. However, it is also desirable that the discharge edge of the platen be positioned as close as possible to the nip of the coil for straight, true, tight winding. Since the coil continuously expands as the coiling progresses so as to continuously relocate the nip, the platen 14 is mounted on the frame 52 for movement relative to the frame and coil.

More specifically, secured to the inner surface of each of the side walls 54 of the frame 52 is a pair of keepers 60 spaced from, and in parallel relation to, each other. The keepers serve as guides for a mounting plate 62 which is positioned adjacent the inner surface of the side walls and is slidable relative thereto between the keepers. The platen 14 is rigidly secured to the mounting plate, as by welding or by suitable fasteners. Since it is desirable that the platen move not only laterally (to the left in FIGS. 1 and 2), but also upwardly, as the coil or coils increase in size, the keepers are inclined at an angle of approximately 60 to the horizontal upwardly and away from the reel 22.

Secured to the platen and extending upwardly from the upper surface thereof adjacent the platen side plates 30 is a threaded rod 64 of relatively large diameter fixed relative to the platen so as not to rotate. Projecting inwardly from each of the frame side walls adjacent the upper edge thereof is a flange 65 which supports a rotatably mounted nut (not shown) enclosed in a housing 66. Each nut is connected by means of a shaft 68 to a gear box 70 which is drivingly connected through a shaft 72 to a motor 74 mounted on a platform 75'- which extends between the side walls 54 of the frame adjacent the upper edges thereof. The connection between the nuts and the motor 74 is such that the nuts will be driven in unison as the motor shaft 72 is rotated. Each nut is threaded onto its adjacent rod 64 so that operation of the motor causes travelling movement of the shaft so as to raise or lower the platen.

Operation of the motor 74 is controlled by a microswitch 76 carried on the forward edge of the bracket 49 and electrically connected to the motor so that when the outer wrap of the coil engages the microswitch incident to an increase in diameter of the coil, the motor is energized for a predetermined period of time so as to move the platen through a short distance. The motor circuit is shown in FIG. 6 wherein the motor 74 is illustrated as a.

reversible capacitance run induction motor having field windings 78 connected in parallel with each other and in series with a capacitance 89. A two-way switch 82 having contacts 84 and 86 is connected in parallel with the capacitance and determines the direction of rotation of the motor armature depending upon which contact is closed. As illustrated, contact 84 when closed causes the motor armature to rotate so as to raise the platen and contact 86 causes the armature to rotate so as to lower the platen.

Connected in series with the motor 74 is a voltage source 88 and microswitch 76, the microswitch being normally open and having a contact 90. When the switch 76 is closed, current flows from one terminal of the voltage source through contact 90 of switch 76 and through contact 84 of switch 82 through motor 80 and back to the opposite terminal of the voltage source.

It is desirable that the switch 76 remain open for a predetermined period of time once it has been opened so that the motor will operate for a sufficient period of time to move the platen a significant distance away from the reel 22 after the microswitch has been moved out of contact with the coil 24. Accordingly, connected in series with the contact 90 is a sensing resistor 92, and connected in parallel with the switch 76 is a normally open shunt switch 94. Also, connected in parallel with the motor 74 is a time delay circuit 96 which is effective when energized to maintain the shunt switch 94 in a closed condition for a predetermined period of time. The time delay circuit is energized by current flowing through the sensing resistor 92. Thus, when the microswitch 76 is closed by engagement by the coil, current flow through the resistor 92 actuates the time delay circuit 96- which closes the switch 94, allowing current to by-pass the switch 76 as long as the switch 94 remains closed.

It is also desirable to lower the platen by means of the motor 74 and, accordingly, a manually operated switch 98 is provided in parallel with the microswitch 76 and is linked to the motor switch 82 so that the switches '82 and 98 are operated in unison. When the switch 98 is closed, current flows from the voltage source 88, through the switch 98, through the contact 86 of the switch 82, through the motor 74, and back to the voltage source 88. The time delay circuit 96 is not energized since current does not flow through the sensing resistor 92. The switch 94, therefore, remains open.

While the above-described arrangement for raising and lowering the platen is believed preferable, it is also contemplated that the platen could be pivoted about an axis adjacent its entry edge such as, for example, an axis coincident with the axis of rotation of the guide roller 46'. Also, one means could be provided for moving the platen vertically and a separate means provided for moving it laterally, with a control for effecting both movements simultaneously or in sequence to accomplish the desired positioning.

It is frequently necessary under present practice, and may occasionally be desirable with the practice of the present invention, to insert cardboard strips between the coil and the outer wrap as the coil is being wound to increase the coil diameter slightly so as to compensate for uneven coiling. Conventionally, insertion is done manually but this practice is dangerous and exposes the operator to serious injury. In order that such insertion may be accomplished automatically, a strip 100 (FIG. 4) divided into segments 102 by lines of perforation 104 is coiled into a roll 106- carried on a shaft 108 (FIG. 1) mounted on the platen 14 so as to move therewith relative to the coil so as to remain in spaced relation to the coil despite the expansion thereof. The strip is connected to the shaft so as to rotate therewith or remain stationary with the shaft, as the case may be. The strip preferably has a width approximately that of one of the bands 12, and the positioning of the single roll 106 relative to any one of the bands 12 may be accomplished by shifting the shaft axially in its bearings or mounting the shaft and hearings on a movable carriage which is shifted.

Positioned beneath the roll 106 is a chute 110* having a configuration enabling it to guide the leading edge of the strip into the nip of the coil 24 as the roll 106 is unwound. Rotation of the shaft 108 to unwind the roll 106 may be accomplished manually or automatically. Preferably, means such as a stop pin on the frame 52 engageable with a shoulder projecting from the shaft 108 (not shown), are provided for locking the shaft against rotation after it has rotated sufiiciently to allow the leading edge of the lead strip 100 to pass into the nip of the coil and becomes attached thereto. Abrupt arrest of the rotation of the roll will place sufficient tension on the strip to sever it at a line of perforation 104, thereby limiting the amount of cardboard inserted to one segment. Of course, further sections may be inserted subsequently if desired.

The device thus described is effective to place a controlled amount of frictional drag on bands being wound into coil or oscillated form and, thus, to impart a tension to the bands. Tension imparted to each of several bands being wound insures a uniform coiling of all of the 'bands and therefore permits a uniformly tight coil to be produced from each band. Additional advantages of the device will be readily apparent to those skilled in the art. For example, by virtue of the use of the device, the coiling apparatus can be halted at any point during the operation and the bands will maintain their position on the platen. Thus, when the end of the strip being slit has been reached in a slitting operation, it is possible to halt the reel with the trailing ends of the bands positioned on the platen and to then place upon the ends of the bands a tape which projects past the ends. When the reel is again rotated, and the ends of the bands reach the coil, the tapes can be easily pressed into engagement with the outer wrap of the coil, as by a roll or the like, to automatically tape the end of the band to the coil.

Although the apparatus described is particularly suited for imparting tension to a ferromagnetic strip, it is con templated that if suitable modifications were made therein it could also be used to impart tension to a strip of non-magnetic material such as copper, aluminum, brass, etc. This could be accomplished by providing a ferromagnetic holddown plate above the platen, the plate being supported by guides so as to enable it to move freely toward and away from the platen in response to forces of attraction set up by the magnets 18. The lower surface of the plate, which would contact the strip and impart a frictional drag thereto, could be provided with a covering such as buff cloth. In such a system, a uniform force could be applied to the holddown plate across its width to apply a uniform force to each band, a result difficult to achieve with other means such as fluid cylinders acting at spaced locations across the plate.

Other advantages to the device disclosed, such as those incident to the automatic insertion of the cardboard sections into the coil, will also be appreciated by those skilled in the art.

While various of the features of the invention have been shown and described with respect to one specific structural embodiment thereof, it should be apparent that various changes may be made in the embodiment shown and described without departing from the scope of the invention.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. A device for creating tension in a traveling strip, said device comprising a platen defining a surface positioned in contact with the strip, a magnet adjacent said platen for causing a force to be applied to the strip urging the strip against said surface of said platen so as to create a frictional drag on the strip, and means provided for moving the platen so as to change the path of travel of the strip.

2. A device in accordance with claim 1, wherein a coil rotating apparatus is positioned adjacent one edge of said platen, and wherein said platen moving means are adapted to automatically maintain said one edge of said platen in a predetermined position relative to the nip formed by the outer Wrap of the coil and the portion of the strip extending from the outer wrap.

3. A device in accordance with claim 2, wherein said strip-contacting surface of said platen is contoured so as to direct the strip along a gradually curved path commencing beneath the coil axis and spaced laterally therefrom in a direction opposite to the direction of travel of the strip and terminating adjacent the uppermost point on said coil.

4. A device for creating tension in a traveling strip, said device comprising a platen defining a surface positioned in contact with the strip, a magnet adjacent said platen for causing a force to be applied to the strip urging the strip against said surface of said platen so as to create a frictional drag on the strip, wherein said means for causing a force to be applied to the strip comprises a magnet capable of drawing a ferromagnetic strip into contact with said surface of said platen, and wherein said platen is provided with a discharge edge last to be contacted by the strip and means for reducing the force of magnetic attraction on the strip at said discharge edge.

5. In a strip coiling apparatus including a coiling mandrel, a device for inserting a spacing sheet between the wraps of the coil as the coil is being formed, said spacing sheet being of minimal length compared to the length of the strip being coiled, said device comprising means supporting a supply of spacing sheets adjacent the nip formed by the outer wrap of the coil and the portion of the strip extending from the outer wrap, and means for guiding a sheet into the said nip.

6. A device in accordance with claim 5, wherein means are provided for maintaining said sheet supporting means and said guide means in a predetermined position relative to the said nip as the coil increases in diameter.

7. A device in accordance with claim 6, wherein said maintaining means include means for moving said sheet supporting means and said guide means away from said mandrel as said coil increases in diameter.

8. A device in accordance with claim 5, wherein said sheets are interconnected in strip form and Wound in a roll, and wherein said sheet supporting means includes a rotatably mounted shaft.

9. A device in accordance with claim 8, wherein said sheets are interconnected along lines of weakness so that they can be easily separated from each other.

10. A device in accordance with claim 5, wherein said guide means comprises an elongated plate extending generally parallel to the axis of the coil and of curved configuration in transverse cross section.

11. A device in accordance with claim 8, wherein means are provided for moving said roll in a direction parallel to the axis of rotation of the mandrel so as to position said roll in alignment with any one of several portions of said mandrel and coils supported thereon.

12. A device for creating tension in and maintaining separation between a plurality of relatively long and closely spaced traveling magnetizable strips of varying slack to be separately and simultaneously coiled upon a take-up reel without auxiliary separating devices directly associated with the reel, comprising a platen located adjacent the reel and defining a nonmagnetic surface common to all of the strips, and magnetic generating means adjacent said platen with all magnetic poles located on one side of the platen for establishing magnetic forces generated by fields applied to each of said strips generally along the length of the strips with the lines of force of each field in each strip traveling in the same direction to individually urge each of said strips against the surface of said platen so as to create an individual frictional drag on each of the strips and also to repel each strip relative any adjacent strip, thus enabling all the strips to be properly tensioned to produce evenly wound tight coils upon the takeup reel and without overlap.

13. The device of claim 12 in which the magnetic means includes an individual electromagnet for each of said strips which establishes an individual frictional drag on each associated strip and repelling forces between adjacent strips.

14. The device of claim 13 comprising means for individually varying the electromagnetic field applied to each of the strips by the electromagnets, and means for varying simultaneously the electromagnetic field applied to all of the strips by all of said electromagnets.

References Cited UNITED STATES PATENTS 2,433,014 12/1947 Rendel 24275.2 X 1,737,127 11/1929 Richey 24267.3 2,731,212 1/1956 Baker 24275.2 3,226,911 1/1966 Vreeland et al 242673 3,380,686 4/1968 Gaudin 24275.2

NATHAN L. MINTZ, Primary Examiner 

